In my mind there are two classes of "personal use" solar.
One is a "toy" or "backup" system, which, IMHO is a system used to run essentials during a power outage, or an RV, tiny home, or shed. Usually single phase, stand-alone, and most of the time doesn't need to meet code. You can normally design one of these systems yourself for a few thousand dollars. A lot of the time (depending on where you live) islanded systems aren't required to meet code, or be installed by a professional, as long as they aren't capable of feeding into the grid in any way. (Don't quote me on that, I'm sure there's other states with ridiculous codes, but here, unless it's attached to the grid, there's no permitting or inspections required).
The other "class" is a system designed to run your HVAC, pool pumps, EV charging, etc. The amount of power produced by those systems almost always requires electrical inspections, code compliance, permits, and professional installation. Even if you have the knowledge to do it yourself, it's generally a serious financial undertaking.